Women who take up BreastCheck are expected to be forced to have a three-year gap between mammograms when it resumes because of Covid-19 restrictions.
Before the pandemic, women were invited for the free screening for breast cancer every two years.
However, HSE national clinical adviser Dr Colm Henry said yesterday that BreastCheck, which will resume in September, will have to operate under a new set of procedures due to the risk associated with Covid-19, which will slow down the service.
"We would have preferred to go back to the way we were but nothing is going back to the way it was in healthcare," he said.
It will mean a three-year cycle of screening, he added.
A backlog of around 80,000 women had built up since the service had to be suspended in March, Dr Henry told Today With Sarah McInerney on RTE radio.
It will be next year before the service will have caught up, he added.
BowelScreen, the programme to detect bowel cancer, will also resume in the autumn.
It was also suspended due to the ability of hospitals to provide colonoscopies, the invasive diagnostic procedures for people referred for further investigation.
Dr Henry said that coronavirus restrictions meant the number of colonoscopies had been halved.
Tallaght Hospital gastroenterologist Dr Anthony O'Connor has previously warned that people who require an urgent colonoscopy should be seen in 28 days under best practice.
"This is not happening for too many people and many more people will be left waiting for far too long unless we see steps taken now," said Dr O'Connor.
"The longer people have to wait, the greater risk we are taking with their outcome if they are found to have cancer."
CervicalCheck resumes this week for high-priority women - those who need a yearly recall - and women who have just joined the service.
Dr Henry estimated there is a backlog of around 100,000 women whose invitation to screening from CervicalCheck has been put on hold since March.
The hope is that this backlog will be cleared by October and the service will be back to normal in February.
He advised women not to go for private smear tests and to continue with CervicalCheck, which offers a continuum of care.
The screening in laboratories now involved HPV testing which increased the chances of abnormalities being picked up, he said.
He said that for every 1,000 women who undergo cervical screening, around 20 will have pre-cancerous abnormalities.
Dr Henry said cervical cancer was slow growing and may be picked up by screening over a lifetime of visits. He strongly urged people who may have symptoms of cancer not to delay and to contact their GP.